Below London, a Blue Whale-Sized 'Concreteberg'

Newser — Arden Dier

A lesson from London: Don't pour concrete down the drain. Otherwise, you might be left with a "concreteberg" like the one currently blocking three central sewers in the Islington borough of the UK capital.

It turns out the 115-ton, 330-foot-long mass discovered during a routine check earlier this month is a bit harder to remove than the 140-ton blob of fat, oils, diapers, and condoms that Alex Saunders of the Thames Water utility once battled successfully, per the Evening Standard.

"Unfortunately in this case it's rock-hard concrete … set to the Victorian brickwork, so we need to chip away at it to get it removed," Saunders tells the BBC.

"This is not the first time damage has been caused by people pouring concrete into our sewers but it's certainly the worst we've seen."

While officials look for the culprits—suspicions have fallen on a construction company—workers are expected to spend up to two months hammering away at the blockage "within the weight range expected of a blue whale," per Utility Week.

They'll use pneumatic drills, a step up from the high-pressure hoses and pickaxes used on the so-called "fatberg," which took nine weeks to remove in 2017.

Meanwhile, tankers will be on site 24 hours a day to pump out sewage in case of heavy rains or other complications. Prep work begins next week.

The BBC puts the cost at nearly $200,000, while the Evening Standard cites Thames Water as saying costs could reach $1.3 million. The utility reportedly spends roughly $23.4 million to clear sewer blockages each year.